1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_LINKAGE_H 3 #define _ASM_X86_LINKAGE_H 4 5 #include <linux/stringify.h> 6 #include <asm/ibt.h> 7 8 #undef notrace 9 #define notrace __attribute__((no_instrument_function)) 10 11 #ifdef CONFIG_X86_32 12 #define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0))) 13 #endif /* CONFIG_X86_32 */ 14 15 #define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT, 0x90; 16 #define __ALIGN_STR __stringify(__ALIGN) 17 18 #if defined(CONFIG_CALL_PADDING) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 19 #define FUNCTION_PADDING .skip CONFIG_FUNCTION_ALIGNMENT, 0x90; 20 #else 21 #define FUNCTION_PADDING 22 #endif 23 24 #if (CONFIG_FUNCTION_ALIGNMENT > 8) && !defined(__DISABLE_EXPORTS) && !defined(BULID_VDSO) 25 # define __FUNC_ALIGN __ALIGN; FUNCTION_PADDING 26 #else 27 # define __FUNC_ALIGN __ALIGN 28 #endif 29 30 #define ASM_FUNC_ALIGN __stringify(__FUNC_ALIGN) 31 #define SYM_F_ALIGN __FUNC_ALIGN 32 33 #ifdef __ASSEMBLY__ 34 35 #if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 36 #define RET jmp __x86_return_thunk 37 #else /* CONFIG_RETPOLINE */ 38 #ifdef CONFIG_SLS 39 #define RET ret; int3 40 #else 41 #define RET ret 42 #endif 43 #endif /* CONFIG_RETPOLINE */ 44 45 #else /* __ASSEMBLY__ */ 46 47 #if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 48 #define ASM_RET "jmp __x86_return_thunk\n\t" 49 #else /* CONFIG_RETPOLINE */ 50 #ifdef CONFIG_SLS 51 #define ASM_RET "ret; int3\n\t" 52 #else 53 #define ASM_RET "ret\n\t" 54 #endif 55 #endif /* CONFIG_RETPOLINE */ 56 57 #endif /* __ASSEMBLY__ */ 58 59 /* 60 * Depending on -fpatchable-function-entry=N,N usage (CONFIG_CALL_PADDING) the 61 * CFI symbol layout changes. 62 * 63 * Without CALL_THUNKS: 64 * 65 * .align FUNCTION_ALIGNMENT 66 * __cfi_##name: 67 * .skip FUNCTION_PADDING, 0x90 68 * .byte 0xb8 69 * .long __kcfi_typeid_##name 70 * name: 71 * 72 * With CALL_THUNKS: 73 * 74 * .align FUNCTION_ALIGNMENT 75 * __cfi_##name: 76 * .byte 0xb8 77 * .long __kcfi_typeid_##name 78 * .skip FUNCTION_PADDING, 0x90 79 * name: 80 * 81 * In both cases the whole thing is FUNCTION_ALIGNMENT aligned and sized. 82 */ 83 84 #ifdef CONFIG_CALL_PADDING 85 #define CFI_PRE_PADDING 86 #define CFI_POST_PADDING .skip CONFIG_FUNCTION_PADDING_BYTES, 0x90; 87 #else 88 #define CFI_PRE_PADDING .skip CONFIG_FUNCTION_PADDING_BYTES, 0x90; 89 #define CFI_POST_PADDING 90 #endif 91 92 #define __CFI_TYPE(name) \ 93 SYM_START(__cfi_##name, SYM_L_LOCAL, SYM_A_NONE) \ 94 CFI_PRE_PADDING \ 95 .byte 0xb8 ASM_NL \ 96 .long __kcfi_typeid_##name ASM_NL \ 97 CFI_POST_PADDING \ 98 SYM_FUNC_END(__cfi_##name) 99 100 /* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type */ 101 #define SYM_TYPED_FUNC_START(name) \ 102 SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) \ 103 ENDBR 104 105 /* SYM_FUNC_START -- use for global functions */ 106 #define SYM_FUNC_START(name) \ 107 SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \ 108 ENDBR 109 110 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ 111 #define SYM_FUNC_START_NOALIGN(name) \ 112 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) \ 113 ENDBR 114 115 /* SYM_FUNC_START_LOCAL -- use for local functions */ 116 #define SYM_FUNC_START_LOCAL(name) \ 117 SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN) \ 118 ENDBR 119 120 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ 121 #define SYM_FUNC_START_LOCAL_NOALIGN(name) \ 122 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) \ 123 ENDBR 124 125 /* SYM_FUNC_START_WEAK -- use for weak functions */ 126 #define SYM_FUNC_START_WEAK(name) \ 127 SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN) \ 128 ENDBR 129 130 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ 131 #define SYM_FUNC_START_WEAK_NOALIGN(name) \ 132 SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \ 133 ENDBR 134 135 #endif /* _ASM_X86_LINKAGE_H */ 136 137